<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>盒子阴影</title>
    <style type="text/css">
        div{
            height: 100px;
            width: 100px;
            border: 1px solid red;
            border-radius: 10px;
            box-shadow: 10px 10px 10px orange; /*外阴影*/
            /*box-shadow: inset 10px 10px 10px orange; !*内阴影*!*/
        }
    </style>
</head>
<body>
    <div></div>
</body>
</html>